Being a manufacturing engineer, I see and appreciate the innovation and beauty of the boxlock much more than the sidelock. It is truly a leap (revolution) in the gun design from the sidelock.
However, the sidelock has had essentially centuries of evolution and refinement. It is THE classic gun design that stirs nostalgia in the mind.
Both are pretty cool to me...for different reasons.
In practical use, I generally find that the boxlocks to have better strength in the stock inletting. I'm fixing a sidelock stock right now that has split the stock in various places within the inletting of the sidelocks, whether due to design or execution.
I think each design has weaknesses and strengths. I'd like to see some more innovation and evolution in the boxlocks. But, change comes slow on something in a niche market as a sxs shotgun.
